Sounding board for stringed instruments



July 25, 1939. H. MOERTEL 2,157,486

SOUNDING BOARD FOR STRINGED INSTRUMENTS Filed March 6, 1937 2 Sheets-Sheet 1 en y floerZ el/ gay-Q0; 7* m July 25, 1939. H. MOERTEL SOUNDING BOARD FOR STRINGED INSTRUMENTS Filed March 6, 1957 2 Sheets-Sheet 2 fiZ/ZTZE? Jieny Jyoeri'eb g9: (96% 7 W Patented July 25, 1939 PATENT OFFICE SOUNDING BOARD FOR STRINGED INSTRUMENTS Henry Moertel, Chicago, Ill.

Application March 6,

4 Claims.

This invention relates to an improvement in a sounding board for stringed instruments, and more particularly to a sounding hole for a resonance box or belly of stringed instruments.

Stringed instruments of the present day type, such as ukeleles, banjo-ukes, mandolins and the like, are constructed with the belly or sounding portion having a sounding hole in the sounding board that is circular in configuration. The purpose of these sounding holes is to'amplify or increase the volume of the sound or tone. The tone created by the strings and the sounding hole, in cooperation with the belly of the instrument, is equalized by sounding ribs disposed on the underface of the sounding board toimprove the quality. The horizontal strumming of the strings upon instruments of this class, in cooperation with the sounding hole in the sounding board, causes a vertical vibration or reciprocation of the sounding board to provide an increased amplification of the tone.

The circular apertures that are used in sounding boards of the present day stringed instruments do not provide enough flexibility in the sounding board to cause the required vibration that is necessary to amplify the tone toits fullest extent. The periphery of the circular aperture does not have sufiicient vibration in order to prevent distortion of the tone in the belly of the instrument. The usual practice is to provide the apertured sounding board with supporting ribs on the underface thereof to eliminate any distorted sounds and thus improve the tone quality.

An object of this invention is to provide a sounding board for stringed instruments that will increase both the volume and quality of the tone of the instrument through sympathetic vibration.

A further object of the invention is the provision of a sounding board for stringed instruments for producing amplified tones without distortion.

An additional object of the invention is to provide a sounding board for stringed instruments having an aperture for creating an increased vibration whereby an increased volume of tone is produced.

A further object of the invention is to create an increased vibration and sensibility in a stringed instrument, with the provision of means to sucure uniformity of vibration in the sounding board of the instrument; and

Still another object of the invention is to provide a sounding board with strengthening ribs 1937, Serial No. 129,409

disposed relative to a tongue-shaped sounding aperture to produce an increased vibration in the instrument in harmony with the vibration of the strings, whereby the volume and quality of the tone is increased.

Numerous other objects and advantages will be apparent throughout the progress of the following specification.

The accompanying drawings illustrate a selected embodiment of the invention and the views therein are as follows:

Figure l is a perspective view of one form of my improved device showing the tongue-shaped sounding aperture;

Figure 2 is a plan view of the body of the instrument with strings omitted and showing the sounding ribs in dotted lines;

Figure 3 is an elevational sectional View taken on the line 3-3 of Figure 2';

Figure 4 is a perspective View of the underface of the sounding board;

Figure 5 is a perspective view of a modified form;

Figure 6 is a top plan view of the body of the instrument shown in Figure 5;

Figure '7 is an elevational sectional View taken on the line of Figure 6; and

Figure 8 is a top plan view showing applicants improvement applied to another type of instrument.

Referring now to the drawings, and more particularly to Figure l, the new improved device discloses a stringed instrument, in this instance a ukelele comprising a body portion I having a belly or top portion or sounding board 2. sides 3 of the body I connect the sounding board 2 to a back portion 4 by gluing or the like. The stringed instrument of this invention utilizes the air space or hollow body portion 5 between the sounding board 2 and the back 4 for developing the space 5 into a sound increasing and resonance space for amplifying the sound. In utilizing the air space to assist in increasing the tone volume, a sound aperture 6 is provided in the sounding board.

The aperture 6 is cut into the board and has a tongue-like configuration, as clearly shown in Figures 1, 2, and 3 and is defined as having a curved section 8 substantially in the shape of a parabola, extending toward the sides of the body I to form semi-circular end curves I0. A convex curve I 2 extends from the semi-circular curves In to complete the aperture 6. The tongueshaped configuration of the aperture with the ut-out curved portions 8 and I2, form the elon- The gated or extended semi-circular curves ill in order to increase the flexibility of the sounding board in proximity of the aperture 6. In view of the increased flexibility of the sounding board 2 created by the tongue-shaped aperture 6, the vibrations of the sounding board, caused by the vibrations of the strings I4, is increased to cooperate with the air space in the belly of the instrument to produce an increased or amplified tone. The horizontal reciprocation of the strings I4 of the instrument will vibrate the strings vertically to cause a vibration in the sounding board 2.

the portion l2 of the sound aperture 6.

The lip I6 is the concentrated vibrating part circular portions ID of the tongue-shaped aperture 6 provide an increased flexibility in the lip portion l6. The increased vibration of the lip it will produce an increased tone volume in the instrument. The strings l4 (Figure l) are secured at the rear of the instrument to the integral tail piece l8, and extend from the tail piece over a bridge 26 past the aperture 6 and along the finger board 22 of the neck 24. The end of the neck 24 has a plurality of apertures 26 corresponding in number to the number of strings on the instrument. These apertures receive the tuning pegs 2B. The

strings l4 are wound around the pegs for tuning the instrument.

It will be evident from the above that the aperture 6 divides the sounding board into two sections, one of the sections being located below and the other being located above the sound hole, as viewed in Figures 1 and 2. The section below the sound hole may be termed the major sounding board section, since it is in this section that the major tone-producing eifect is generated. The other or upper section of the sounding board serves substantially only to complete the upper portion of the instrument and, therefore, may be termed the minor sounding board section. It should be noted, moreover, that the major sounding board section cooperates with the bridge 20 to additionally receive and transmit the vibrations induced by the motion of the strings.

The sounding board 2 has on its underside, as shown in dotted lines of Figure 2, a plurality of sounding ribs 30, 32 and 34. The sounding ribs cooperate with the sounding board and the aperture 6 to equalize the vibrations of the board, and thus neutralize the tone more evenly, which consequently improves the quality of the tone. The sounding ribs are glued to the underside of the sounding board 2 in order to increase the resistance of the sounding board against any distorted vibration. The aperture 6 and the lip l6 increase the volume of the tone, but to equalize the volume and cause a deeper and fuller quality in the tone, the sounding ribs are necessary. The neutralization or equalizing of the tone by the sounding ribs is such that the higher tones are clearly resonant with the belly I of the stringed instrument. The sounding ribs 3!] and 32 are placed near the aperture and on each side thereof to produce more resistance at that point, so that the higher tones that are created by the strings and the vibratory lip in proximity to that point will be clear and full.

The back rib 34 (Figures 2 and 4) has a substantially circular increased central portion 36. This sounding rib 34 is placed on the underface of the sounding board 2 near the back supporting block 38 and in a position immediately below Thesounding board has a lip I6 immediately adjacent where the bridge 20 of the instrument will be placed on the top portion of the sounding board. The sounding rib 34 is disposed immediately underneath the bridge in order that the tone that is produced in the rear of the belly will be spread out or neutralized by the enlarged portion 36 with the tone created near the sound aperture 6 to provide an equalized resonance. This is because the enlarged portion 36 of the rib 34 has the effect of spreading the tone more evenly, especially the higher tones that are created by the strings of the instrument. The rib 34 cooperates with the ribs 36 and 32 for equalizing the tone quality throughout the belly of the instrument. In this manner the tones are clear and full throughout the belly of the instrument, rather than being clear in one portion and distorted in another. It will be understood that the back sounding rib may be dispensed with, and only the front sounding ribs need be utilized in the production of a cheaper instrument.

The sounding aperture is shown in Figures 5, 6 and 7, applied to a stringed instrument of the banjo-uke type. The body 44 of the instrument comprises a top circular sounding board 46 connected by the side members 48 with the lower or bottom board 50. In instruments of this type that utilize a circular sounding board, the diameter of the board is unusually, wide. Consequently, the aperture must extend substantially across the width of the board to vibrate with the required frequency exacted of the wider belly in order to fully amplify the tone. The tongueshaped aperture 52*(Figures 5 and 6) is identical in design with that of the aperture disclosed in Figures 1 and 4. The aperture 52 is defined by a curved parabola 54 extending toward the sides 48 of the sounding board 46 to form semi-circular curved recesses 56 (Fig. 6). A convex curve 58 extends from the recess 56 to complete the aperture 52. The edge or periphery of the curve 58 forms a vibratory lip 66. The shape of this sound aperture has the same effect of increasing the vibration of the sounding board to produce an amplified volume, as h-ereinbefore described.

The instrument shown in Figures 5 and 6 has a tail piece 43, bridge 45, neck portion 41, strings 49 and pegs 5|.

A sounding rib 62 is placed immediately to the rear of the sound hole 52 on the underface of the sounding board 46. The sounding rib 62 is supported by blocks 64 glued on each side in the belly of the instrument between the sounding board 46 and the bottom portion 56 and in alignment with the sounding rib 62. are used in instruments that have a wide belly portion in order to partially support the sounding rib 62. The additional support of the sounding rib is necessary in order to provide the proper resistance to the sounding board 46 necessary to equalize the tone. A sounding rib 66 may be placed in the rear of the sounding board 46 to assist in the equalization of the tone caused by the vibration of the strings andthe sounding board. In Figure 8 the sound aperture 64, blocks 68, ribs 1!! and '12 are shown applied to a mandolin which also has an increased belly diameter. The application is identical as that applied to the banjo-uke in Figures 5 and 6.

From the foregoing it will be apparent that These blocks 64 vertical reciprocation or vibration of the sounding board. This vertical reciprocation or vibration in cooperation with the vibration of the strings of the instrument produce an increased volume of tone; furthermore, that the placing of the sounding ribs will strengthen the resistance of the sounding board at certain points thereon to equalize or spread out the tone to enhance the quality thereof.

By the term free edge, as applied to the edge of the lip !2 throughout the claims, is meant that the edge is free to vibrate under the influence of the vibration of the strings without being restricted by securement to adjacent walls or the like.

Changes may be made in the form, construction and arrangement of the parts Without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes as fairly fall Within the scope of the following claims.

What is claimed a: new and desired to be secured by Letters Patent of the United States is as follows:

1. For use in a stringed musical instrument, a relatively flat sounding board having an aperture extending generally transversely across the board, said aperture being of substantial width adjacent its mid-portion and tapering to form relatively narrow extremities adjacent the opposite edges of the board, one edge of the opening being concave and the other being convex, said aperture providing major and minor sounding board sections, said major section providing said convex edge and forming a tongue-shaped portion extending into said aperture and cooperating with the instru ment to vibrate ireely under the influence of the strings.

2. For use in a stringed musical instrument, a relatively flat sounding board having an aperture extending generally transversely across the board and being defined by a pair of generally transversely extending edges, said aperture being of substantial width adjacent its mid-portion and decreasing in width to form relatively narrow extremities adjacent the opposite edges of the board, one edge of the opening being concave and the other being substantially convex, said aperture substantially dividing said sounding board into major and minor sounding board sections, said major section providing said convex edge and forming a tongue-shaped portion extending into said aperture and cooperating with the instrument to vibrate freely under the influence of the strings.

3. For use in a stringed musical instrument, a relatively fiat sounding board having an aperture extending generally transversely across the board and being defined by a pair of generally transversely extending edges, said aperture being of substantial width adjacent its mid-portion and decreasing in width to form relatively narrow extremities adjacent the opposite edges of the board, one edge of the opening being concave and the other being substantially convex, said aperture substantially dividing said sounding board into major and minor sounding board sections, said major section providing said convex edge and forming a tongue-shaped portion extending into said aperture and cooperating with the instrument to vibrate freely under the influence of the strings, said major section being provided with a rib extending substantially transversely across the board and adjacent the said extremities of said aperture.

4. For use in a musical instrument having a sounding box, said sounding box comprising a relatively flat sounding board having an aperture extending generally transversely across the board and substantially to the edges thereof and dividing the board into major and minor sounding board sections, said aperture being defined on one side by a transversely extending edge of said minor section and on the other side by a generally transversely extending edge of the major section, the edge of said minor section being generally concave, the edge of said major section extending in a direction relatively straight with respect to the said concave edge and providing with said concave edge an aperture of substantial width adjacent its mid-portion, decreasing in width to form relatively narrow extremities adjacent the side edges of the board, the transversely extending edge of said major section being transversely free from attachment and providing an edge adjacent said aperture cooperating with the strings of said instrument to vibrate freely.

HENRY MOERTEL. 

